The slide rail device for a vehicle disclosed in Patent Literature 1 is equipped with a left and right pair of lower rails which extend in a forward/rearward direction and are fixed to a vehicle interior floor, and a left and right pair of upper rails which supports a seating portion of a seat and are slidably supported by the left and right lower rails, a left and right pair of locking mechanisms which are provided between the left and right upper rails and the left and right lower rails and switch between an unlocked state to allow the upper rails to slide with respect to the lower rails and a locked state to prevent the upper rails from sliding with respect to the lower rails, a left and right pair of lever brackets which are supported by the upper rails to be capable of rotating in a vertical direction between a lock position to allow the locking mechanisms to be in a locked state, and an unlock position in which front ends of the lever brackets move more upward than those at the lock position and allow the locking mechanisms to move into a unlocked state, and a rod lever both left and right rear ends of which are connected to the front ends of the left and right lever brackets. Support pins (rotation shafts) which extend in a horizontal direction are fixed to the rear ends of both side portions of the rod lever, and these support pins are rotatably engaged in bearing holes formed at the front ends of the left and right lever brackets. In addition, the left and right lever brackets are provided at the front ends thereof with stopper portions which prevent the rod lever from further rotating upward with respect to the lever brackets at a predetermined position, and coil springs which bias and rotate the rod lever upwardly with respect to the lever brackets are installed between the rear ends of both side portions of the rod lever and the left and right lever brackets, respectively.
Therefore, upon an occupant pulling up the rod lever, this operational force is transmitted from the rod lever to the left and right lever brackets to cause each lever bracket to rotate to the unlock position, which causes the locking mechanisms in a locked state to change to an unlocked state.
On the other hand, in the case where a passenger depresses the rod lever against the biasing force of the coil springs, the state of the locking mechanisms does not change since the rotational force of the rod lever is not transmitted to the left and right lever brackets.
In addition, when the locking mechanisms are in a locked state, if the rear end of one lower rail is raised from a vehicle floor (moves more upward than the front end of the same) by, e.g., a collision of another vehicle with a vehicle equipped with the aforementioned slide rail device (slide seat), the front of the lever bracket on the upper rail side supported by the aforementioned lower rail moves (rotates) further downward than the rear of the same lever bracket, this downward moving force is transmitted from the aforementioned lever bracket to one end (side portion) of the rod lever. Thereupon, the other end (side portion) of the rod lever also moves (rotates) downward; however, this downward moving force (rotational force) of the other side portion is not transmitted to the other lever bracket, so that the locked state of the locking mechanism which is linked with the other lever bracket is maintained. Therefore, even if a collision or the like occurs, the seat (the upper rails) does not unexpectedly slide with respect to the lower rails, which is safe.